If a single book is 30 plus hours to read it'll never be a successful series.
To be fair, at least around 1/5 or even 1/3 of each book is
- Recaps of stuff that happened as the storytelling pans towards PoV character.
- Descriptions of scenery.
- Slow as hell travel scenes
On TV, you can skip the recaps, scenery is implicit, and the travel montages can be made much faster.
I mean, story summaries are pretty much:
- Book 1, works as an independent story, the three country boys and two gals are yanked onto the adventure, during which they learn a bunch of lore and at the end they have a bossfight
- Book 2&3, the boss was just a sub-boss of the real Big Bad, need to grab a bunch of gear. Gals go to level up in wizard school, boys start hunting for that extra gear. Add a couple of prophecies into the mix.
- Book 4-7: The main character does a bunch of level ups with Fremen (oh wait, Aiel) and defeats a few more bosses. A new group (Seachan) show up in force, while they have so far been only hinted at.
- Book 8-11: Folks bounce around and nothing much happens, but getting a bunch of setup for the final battle.
- Books 12-14: Payoff to the previous four books set-up. Plotlines finally getting tied up with massive battles everywhere.
(Yeah, personally at around book 9 I stopped for several years, but then when news got around that the series had finally finished, I got around to reading them. It was ok-ish in the end, but I'll probably not even try reading them again).
Anyway, there's so much filler in the books that condensing those to around Book 1 = Season 1 and then 1 season for every 2-3 books is not *that* difficult if you just cull a bit of the plot kudzu.